Creating the Hash

All URLs on Gravatar are based on the use of the hashed value of an email address. Images and profiles are both accessed via the hash of an email, and it is considered the primary way of identifying an identity within the system. To ensure a consistent and accurate hash, the following steps should be taken to create a hash:

Trim leading and trailing whitespace from an email address

Force all characters to lower-case

md5 hash the final string

As an example, let's say we start with "MyEmailAddress@example.com " (note the trailing space which our hypothetical user entered by mistake). If we md5 encode that string directly, we get the following (in PHP):